The Los Alamos National Laboratory has replaced numerous Chinese components in all of its computer systems over security concerns, according to the Reuters News Agency.

The parts in question are network switches manufactured by H3C Technologies. Network switches are used to manage data traffic.

Reuters learned of LANL’s concerns through a Nov. 5 letter written by the acting chief information officer at LANL to the Department of Energy’s national nuclear security administration’s manager for safeguards and security.

NNSA did not respond to a request for comment.

The letter detailed how an unidentified network engineer at LANL alerted authorities that the devices were being installed on the networks, and that there may be some already installed on the networks.

It is undetermined at this point whether any security breach occurred, but the letter went on to say the lab’s counter-intelligence unit in October examined “sensitive networks” and “determined that a small number of the devices installed on one network were H3C devices. Two devices used in isolated cases were promptly replaced,” the letter said.

The letter also reportedly says the lab is conducting an investigation into whether “any potential risk associated with any H3C devices that may remain in service until replacements can be obtained.”

The letter said “We would like to emphasize that (Los Alamos) has taken this issue seriously, and implemented expeditious and proactive steps to address it.”

According to Reuters, a Washington D.C. based corporate representative of Huwei, one of the manufacturers of the switches, dismissed the idea that his company’s computer components posed any sort of security breach at all to America’s national security.

“There has never been a shred of substantive proof that Huawei gear is any less secure than that of our competitors, all of which rely on common global standards, supply chains, coding and manufacturing, said William Plummer, Huawei’s vice president of external affairs in an email to Reuters

“Blackballing legitimate multinationals based on country of origin is reckless, both in terms of fostering a dangerously false sense of cyber-security and in threatening the free and fair global trading system that the US has championed for the last 60-plus years.”

However, according to Reuters, the U.S. House intelligence committee produced a report in October saying Huawei and another manufacturer of the switches, ZTE.

“cannot be trusted to be free of foreign state influence” and pose “a security threat to the United States and to our systems.”